diff --git a/app/src/main/java/org/isoron/uhabits/commands/DeleteHabitsCommand.java b/app/src/main/java/org/isoron/uhabits/commands/DeleteHabitsCommand.java
index 6dff1f59d..7e4e201eb 100644
--- a/app/src/main/java/org/isoron/uhabits/commands/DeleteHabitsCommand.java
+++ b/app/src/main/java/org/isoron/uhabits/commands/DeleteHabitsCommand.java
@@ -41,7 +41,7 @@ public class DeleteHabitsCommand extends Command
     @Override
     public void undo()
     {
-
+        throw new UnsupportedOperationException();
     }
 
     public Integer getExecuteStringId()